FNA: Quercus pacifica vs. Quercus minima

	Quercus pacifica	Quercus minima
	Channel Island scrub oak, island scrub oak, Pacific oak	dwarf live oak, minimal oak
Habit	Shrubs, rarely small trees, subevergreen, shrubs to 2 m, trees to 5 m or taller.	Shrubs, subevergreen or evergreen, low, rhizomatous, forming clonal patches of straight, often unbranched stems 0.2-0.7(-2) m. Bark light gray or brown, smooth.
Bark	scaly on older branches and trunk.
Twigs	brownish or reddish, minutely puberulent, becoming glabrate and gray with age.	light gray, 1.5-3 mm diam., glabrous or very finely tomentulose and glabrate in 2d year.
Buds	light or chestnut brown, ovate or globose, 2-3 × 1-2 mm.	dark gray-brown, globose, 0.5-1(-1.5) mm; scale margins glabrous or puberulent.
Leaves	blade obovate or oblong, planar to moderately convex or undulate, 15-40 × 7-20(-40) mm, base cuneate or rounded, attenuate-decurrent along petiole, margins minutely cartilaginous, entire or with 1-5 irregular teeth on each side, secondary veins obscure, 1-5 on each side, apex blunt or rounded, occasionally subacute with mucronate tip; surfaces abaxially waxy, glandular, with scattered minute, flat, appressed, ± 8-rayed stellate hairs, not obscuring surface, adaxially green, glossy, glabrate or with minute, scattered, stellate hairs.	blade obovate to oblanceolate, sometimes orbiculate or lance-ovate, often asymmetric, 40-120 × 20-50 mm proximally on shoots, narrowly elliptic, 20-60 × 5-20 mm distally on shoots, base cuneate, rarely truncate or cordate, margins minutely revolute or flat, coarsely and irregularly 1-5 toothed on each side (proximal leaves of shoots) or entire (distal leaves on shoots), teeth mucronate (rarely spinose in suckers or juveniles), secondary veins obscure, 4-10(-12) on each side, usually 4-6 in proximal leaves, apex obtuse-rounded or acute; surfaces abaxially whitish or glaucous, densely covered with minute, appressed, fused-stellate hairs, light green and glabrate in shade leaves, adaxially dark or light green, glossy, glabrous or with minute, scattered, stellate hairs.
Acorns	paired or solitary in leaf axil, subsessile, rarely pedunculate in teratological forms; cup hemispheric to turbinate, to 15 mm deep × 20 mm wide, enclosing only 1/4-1/2 nut, scales moderately to heavily tuberculate, irregularly formed; nut light brown, acute-cylindric or fusiform, tapered, (15-)20-30 × (6-)9-15 m, apex acute, glabrate.	1-3, on peduncle 3-30 mm; cup hemispheric or deeply goblet-shaped, (8-)10-15 mm deep × 6-15 mm wide, base often constricted, scales whitish or grayish, thickened basally, keeled, acute-attenuate, tomentulose, tips reddish, glabrous or puberulent; nut dark brown, narrowly ovoid or subcylindric, 13-22(-25) × 8-15 mm, glabrous.
Cotyledons	distinct.	connate.

	Quercus pacifica	Quercus minima
Phenology	Flowering spring.	Flowering spring.
Habitat	Chaparral, oak woodlands, margins of grasslands, understory in closed-cone pine stands	Coastal plain, open evergreen woodlands and scrublands on deep sandy soils, often as understory with pines
Elevation	0-300 m (0-1000 ft)	0-200 m (0-700 ft)
Distribution	CA [WildflowerSearch map] [BONAP county map]	FL; GA; MS; NC; SC [WildflowerSearch map] [BONAP county map]
Discussion	Of conservation concern. Quercus pacifica is endemic on three of the California Channel Islands: Santa Cruz, Santa Catalina, and Santa Rosa. It is not known from the mainland, but it bears a superficial similarity to some of the tree forms that are putative hybrids between Q. engelmannii and Q. cornelius-mulleri in San Diego County. The latter populations, sometimes treated as Q. ×acutidens, differ in having much greater variability in leaf shape; thicker, more leathery leaves; denser abaxial leaf vestiture; much smaller hairs, having more than 10 rays; and variable levels of connation of cotyledons (always distinct in Q. pacifica). Quercus pacifica appears to be most closely related to Q. douglasii, whether by direct descent or by introgression with another species no longer extant on the islands. Quercus ×macdonaldii Greene (as a species) [= Quercus dumosa var. macdonaldii (Greene) Jepson] is a stabilized hybrid complex between Quercus pacifica and Q. lobata Née. The plants tend to be small to moderate trees with leaves that resemble those of Q. lobata; the leaves are much more shallowly lobed and always less than two-thirds the distance from the margin to the midrib. Quercus ×macdonaldii is known from Santa Rosa, Santa Cruz, and Santa Catalina islands. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Quercus minima is one of the most distinctive oaks of southeastern United States in morphology, habit, and habitat. It is one of our most strongly rhizomatous species, and it flowers and fruits as early as three years from seed, on vertical stems as small as 0.2-0.3 m. Other related live oaks of Quercus series Virentes (see C. H. Muller 1961) can produce rhizomatous clonal patches as well, but these typically do not bear fruit, are usually associated with large shrub or tree forms, and probably represent response to fire and/or drought conditions. Because of the juvenile phases in other live oaks that may resemble Q. minima, it is necessary to evaluate form and reproductive capacity within populations to identify those species accurately. Putative hybrid swarms between Quercus minima and Q. chapmanii occur along the eastern side of Florida. These are rhizomatous shrubs with leaves somewhat intermediate between the two parents. The leaves are broadly rounded apically and basally, and sparsely stellate abaxially. The fruit resembles that of Q. minima. Material of such affinity, but with larger nuts (to 25 mm), was the basis for Q. rolfsii Small. More data on variation in cotyledon fusion in the putative hybrid swarms would be useful because Q. minima has connate cotyledons and those of Q. chapmanii are distinct. Quercus minima has been reported from coastal Texas (C. H. Muller 1970), but that material is probably best referred to Q. fusiformis and possible introgressants from Q. virginiana and Q. oleoides. Typical Q. minima is not known from west of Mississippi. The Texas populations that have been referred here lack leaf dimorphism, leaf shape, and venation of Q. minima. Instead, they seem to be part of an extremely variable complex of erect shrubs, rhizomatous shrubs, and trees that have leaves varying in form between those of Q. fusiformis and Q. oleoides (e.g., the type of Q. oleoides var. quaterna C. H. Muller). If Q. minima occurred on the Texas coast in the past, its presence there has been so diluted by introgression that it is not now recognizable by the very distinctive and reliable characteristics that are used to identify it. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 3.	FNA vol. 3.
Parent taxa	Fagaceae > Quercus > sect. Quercus	Fagaceae > Quercus > sect. Quercus
Sibling taxa	Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii	Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Synonyms	Q. dumosa var. polycarpa	Q. virginiana var. minima, Q. virens var. dentata, Q. virginiana var. dentata
Name authority	Nixon & C. H. Muller: Novon 4: 391. (1994)	(Sargent) Small: Bull. Torrey Bot. Club 24: 438. (1897)
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Quercus minima

Channel Island scrub oak, island scrub oak, Pacific oak

dwarf live oak, minimal oak

Habit

Shrubs, rarely small trees, subevergreen, shrubs to 2 m, trees to 5 m or taller.

Shrubs, subevergreen or evergreen, low, rhizomatous, forming clonal patches of straight, often unbranched stems 0.2-0.7(-2) m. Bark light gray or brown, smooth.

Bark

scaly on older branches and trunk.

Twigs

brownish or reddish, minutely puberulent, becoming glabrate and gray with age.

light gray, 1.5-3 mm diam., glabrous or very finely tomentulose and glabrate in 2d year.

Buds

light or chestnut brown, ovate or globose, 2-3 × 1-2 mm.

dark gray-brown, globose, 0.5-1(-1.5) mm;

scale margins glabrous or puberulent.

Leaves

blade obovate or oblong, planar to moderately convex or undulate, 15-40 × 7-20(-40) mm, base cuneate or rounded, attenuate-decurrent along petiole, margins minutely cartilaginous, entire or with 1-5 irregular teeth on each side, secondary veins obscure, 1-5 on each side, apex blunt or rounded, occasionally subacute with mucronate tip;

surfaces abaxially waxy, glandular, with scattered minute, flat, appressed, ± 8-rayed stellate hairs, not obscuring surface, adaxially green, glossy, glabrate or with minute, scattered, stellate hairs.

blade obovate to oblanceolate, sometimes orbiculate or lance-ovate, often asymmetric, 40-120 × 20-50 mm proximally on shoots, narrowly elliptic, 20-60 × 5-20 mm distally on shoots, base cuneate, rarely truncate or cordate, margins minutely revolute or flat, coarsely and irregularly 1-5 toothed on each side (proximal leaves of shoots) or entire (distal leaves on shoots), teeth mucronate (rarely spinose in suckers or juveniles), secondary veins obscure, 4-10(-12) on each side, usually 4-6 in proximal leaves, apex obtuse-rounded or acute;

surfaces abaxially whitish or glaucous, densely covered with minute, appressed, fused-stellate hairs, light green and glabrate in shade leaves, adaxially dark or light green, glossy, glabrous or with minute, scattered, stellate hairs.

Acorns

paired or solitary in leaf axil, subsessile, rarely pedunculate in teratological forms;

cup hemispheric to turbinate, to 15 mm deep × 20 mm wide, enclosing only 1/4-1/2 nut, scales moderately to heavily tuberculate, irregularly formed;

nut light brown, acute-cylindric or fusiform, tapered, (15-)20-30 × (6-)9-15 m, apex acute, glabrate.

1-3, on peduncle 3-30 mm;

cup hemispheric or deeply goblet-shaped, (8-)10-15 mm deep × 6-15 mm wide, base often constricted, scales whitish or grayish, thickened basally, keeled, acute-attenuate, tomentulose, tips reddish, glabrous or puberulent;

nut dark brown, narrowly ovoid or subcylindric, 13-22(-25) × 8-15 mm, glabrous.

Cotyledons

distinct.

connate.

Quercus pacifica

Quercus minima

Phenology

Flowering spring.

Habitat

Chaparral, oak woodlands, margins of grasslands, understory in closed-cone pine stands

Coastal plain, open evergreen woodlands and scrublands on deep sandy soils, often as understory with pines

Elevation

0-300 m (0-1000 ft)

0-200 m (0-700 ft)

Distribution

[WildflowerSearch map]

[BONAP county map]

FL; GA; MS; NC; SC

[WildflowerSearch map]

[BONAP county map]

Discussion

Of conservation concern.

Quercus pacifica is endemic on three of the California Channel Islands: Santa Cruz, Santa Catalina, and Santa Rosa. It is not known from the mainland, but it bears a superficial similarity to some of the tree forms that are putative hybrids between Q. engelmannii and Q. cornelius-mulleri in San Diego County. The latter populations, sometimes treated as Q. ×acutidens, differ in having much greater variability in leaf shape; thicker, more leathery leaves; denser abaxial leaf vestiture; much smaller hairs, having more than 10 rays; and variable levels of connation of cotyledons (always distinct in Q. pacifica). Quercus pacifica appears to be most closely related to Q. douglasii, whether by direct descent or by introgression with another species no longer extant on the islands.

Quercus ×macdonaldii Greene (as a species) [= Quercus dumosa var. macdonaldii (Greene) Jepson] is a stabilized hybrid complex between Quercus pacifica and Q. lobata Née. The plants tend to be small to moderate trees with leaves that resemble those of Q. lobata; the leaves are much more shallowly lobed and always less than two-thirds the distance from the margin to the midrib. Quercus ×macdonaldii is known from Santa Rosa, Santa Cruz, and Santa Catalina islands.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Quercus minima is one of the most distinctive oaks of southeastern United States in morphology, habit, and habitat. It is one of our most strongly rhizomatous species, and it flowers and fruits as early as three years from seed, on vertical stems as small as 0.2-0.3 m. Other related live oaks of Quercus series Virentes (see C. H. Muller 1961) can produce rhizomatous clonal patches as well, but these typically do not bear fruit, are usually associated with large shrub or tree forms, and probably represent response to fire and/or drought conditions. Because of the juvenile phases in other live oaks that may resemble Q. minima, it is necessary to evaluate form and reproductive capacity within populations to identify those species accurately.

Putative hybrid swarms between Quercus minima and Q. chapmanii occur along the eastern side of Florida. These are rhizomatous shrubs with leaves somewhat intermediate between the two parents. The leaves are broadly rounded apically and basally, and sparsely stellate abaxially. The fruit resembles that of Q. minima. Material of such affinity, but with larger nuts (to 25 mm), was the basis for Q. rolfsii Small. More data on variation in cotyledon fusion in the putative hybrid swarms would be useful because Q. minima has connate cotyledons and those of Q. chapmanii are distinct.

Quercus minima has been reported from coastal Texas (C. H. Muller 1970), but that material is probably best referred to Q. fusiformis and possible introgressants from Q. virginiana and Q. oleoides. Typical Q. minima is not known from west of Mississippi. The Texas populations that have been referred here lack leaf dimorphism, leaf shape, and venation of Q. minima. Instead, they seem to be part of an extremely variable complex of erect shrubs, rhizomatous shrubs, and trees that have leaves varying in form between those of Q. fusiformis and Q. oleoides (e.g., the type of Q. oleoides var. quaterna C. H. Muller). If Q. minima occurred on the Texas coast in the past, its presence there has been so diluted by introgression that it is not now recognizable by the very distinctive and reliable characteristics that are used to identify it.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source

FNA vol. 3.

Parent taxa

Fagaceae > Quercus > sect. Quercus

Sibling taxa

Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii

Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii

Synonyms

Q. dumosa var. polycarpa

Q. virginiana var. minima, Q. virens var. dentata, Q. virginiana var. dentata

Name authority

Nixon & C. H. Muller: Novon 4: 391. (1994)

(Sargent) Small: Bull. Torrey Bot. Club 24: 438. (1897)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

Choose a data source: Flora of North America

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Quercus pacifica

Quercus minima

Quercus pacifica

Quercus minima